Path Traversal Vulnerability in IBM Langflow OSS

IBM Langflow OSS, an open-source visual workflow tool, contains a critical path traversal vulnerability identified as CVE-2026-12942. The vulnerability resides in how the application handles user-supplied input within URL requests. An unauthenticated remote attacker can bypass existing directory restrictions by injecting 'dot-dot' (../) sequence characters into the request path. Successful exploitation of this flaw grants the attacker the ability to read arbitrary files from the underlying server filesystem. This represents a significant risk as it can lead to the exposure of sensitive configuration files, environment variables, or other stored data, depending on the server's permissions. The flaw impacts versions 1.0.0 through 1.10.1.

Impact

Successful exploitation allows for unauthorized information disclosure, potentially exposing critical system files or secrets stored within the application's environment. This can facilitate further attacks by providing attackers with the necessary intelligence to elevate privileges or pivot within the network. The vulnerability is considered highly exploitable given the lack of authentication required to perform the traversal.

Recommendation

• Upgrade to a patched version of IBM Langflow OSS immediately upon availability from the vendor.
• Implement request validation and path normalization at the web application firewall (WAF) or reverse proxy layer to detect and block sequences containing directory traversal characters ('../').
• Deploy the provided Sigma rule to detect incoming HTTP requests containing suspicious traversal patterns within the URI.